1. Field
This disclosure relates generally to semiconductor devices, and more specifically, to MOSFET devices featuring a ternary oxide overlying a compound semiconductor surface, and more specifically, an indium-containing or gallium-containing compound semiconductor surface and method of making the same.
2. Related Art
State of the art compound semiconductor metal-oxide-semiconductor field effect transistors (MOSFETs) are known to be fabricated with a gate dielectric stack that consists of a Ga2O3 template layer with a GdGaO layer on top of GaAs-based devices. The Ga2O3 layer serves to unpin the semiconductor Fermi level and the GdGaO provides a high resistivity layer with the required conduction band offsets to reduce gate leakage. However, for indium phosphide based (InP-based) devices that have enhanced properties due to the higher mobility of high In composition in the InGaAs channel layers leading to higher drive current and frequency, a suitable gate dielectric for the InGaAs/InP system is lacking. Similarly, for indium antimonide based (InSb-based) devices that have enhanced properties due to their higher mobility leading to higher drive current and operating frequency, a suitable gate dielectric for Sb-containing compound semiconductor system is lacking.
Accordingly, there is a need for an improved method and apparatus for overcoming the problems in the art as discussed above.